This mechanism is generally called a “handover” mechanism.
According to classic techniques, the handover procedure requires a phase of negotiation between radio access points, requiring a phase of discovery of the neighboring access points.
Various approaches have been proposed to simplify and accelerate the handover procedure. Thus, there is a known technique disclosed in Y. Khouaja, K. Guillouard, J M Bonnin, Ph. Bertin, “Hierarchical Mobility Controlled by the Network”, Multi-Access, Mobility and Teletraffic for Wireless Communications, vol. 6, 2002 implementing a mobility manager (MM) in a database based on the IP protocol by which the network operator can efficiently control the mobility of the IP terminals (also called mobile nodes or MN (the various abbreviations used here below are defined in section 6.1) that it serves.
The essential elements of this approach are the following:                sending information back from MN to MM on the quality of transmission between MN and various neighboring access points (AP) when the quality of transmission with the current AP reaches a critical threshold.        requesting a change of AP by the MN (without specifying the new target AP);        change of AP managed by the MM with duplication of the data transmitted by the MN (IP Packets) between the MM and the former AP on the one hand and between the MM and the new AP on the other hand;        implanting one MM per mobility domain containing a certain number of APs associated with a database (DB).        
One drawback of this technique is that the terminal must perform a measurement phase for its current point as well as for all the neighboring access points indicated by the network. As soon as the radio signal of the terminal falls below a critical threshold, it must send back all the measurements obtained (relative to current access point and neighboring access points). These operations consume processing time and memory capacity, especially for low-capacity or “light” terminals.
Other improvements have been proposed, especially by the firm CISCO. These improvements include more specifically the technique known as the CISCO WDS Solution (registered marks). The value of these techniques is that they optimize handover time for a terminal passing from one access point to another in a secure WLAN network. These main characteristics are:                reducing the access point discovery phase through a list of neighboring access points that are built dynamically as and when the terminals move about;        accelerating the authentication phase by basing the operation on a localized authentication server.        
However, even though reduced, the phase of discovery of the point of access is still present.